1. Field of the Invention
With reference to the classification of art as established in and by the United States Patent Office the present invention is believed to be found in the general class entitled, "Winding and Reeling" (Class 242) and in the subclass therein entitled, "Multiple Reel--simultaneous operation " (Subclass 56.9) and in the subclass entitled, "Contractable or Expansible--With Inflatable means" (Subclass 72 B)
2. Description of the Prior Art
Expanding mandrels adapted to hold and release cores of strip material that is to be wound are well known. In particular the use of pneumatics for expanding the movable leaf portions into and from a gripping condition is shown in Applicants prior U.S. Pat. No. 3,825,167 as issued July 23, 1974; 3,917,187 as issued Nov. 4, 1975; 3,937,412 as issued Feb. 10, 1976 and 4,124,173 as issued Nov. 7, 1978. Also to be noted in U.S. Pat. No. 4,220,291 to PAPA as issued Sept. 2, 1980. These and other attempts to wind a plurality of narrow strips of material on cores contemplate a build-up and needed slip to accommodate the changes in the diameter of the winding of the strips. Said slip control resulted in some strips having too much tension and some strips having not enough tension to produce the desired winding result.
U.S. Pat. No. 4,220,291 to PAPA discloses an expandible chuck much like that of Applicants apparatus above identified but proposes to apply very localized pressure on narrow cores by applying pressure through balls carried in conical apertures. The ball concept does not provide positive driving ability when the spools are mounted. In fact, at the outset of winding at core diameter there is no positive drive and certainly not at the diameter of the finished strip. When tried, balls have proved to be too localized and have a tendency to rotate. The tapered receiving apertures to retain these balls tend to become oversize and/or worn to the extent that the balls fall from said formed apertures after a short use. The present invention is a modification of Applicant's U.S. Pat. No. 3,825,167 and includes hardened and replaceable button end members which are carried by support saddles that rest upon and are moved by pneumatically actuated tubing.